The Federal Railroad Administration (FRA) requires periodic inspection of railways to ensure safety of track structures. The inspection requirements of railways are set forth in 49 CFR Part 213. In addition to other types of required inspections, such as the biannual inspection of tracks with ultrasonic and magnetic testers for internal defects, visual inspections of the tracks are required.
49 CFR 213.233 (b) mandates that each inspection must be made on foot or by riding over the track in a vehicle at a speed that allows the person making the inspection to visually inspect the track structure for compliance. However, mechanical, electrical and other track inspection devices may be used to supplement visual inspection. If a vehicle is used for visual inspection, the speed of the vehicle may not be more than 5 miles per hour when passing over track crossings, highway crossings, or switches.
The frequency of such visual inspection varies with the class of the track. Each track is classified depending on, for instance, the type of use to which the track is subjected, e.g., freight, hazardous freight, passenger, etc.; the speed for which the track is rated; the number and weight of the cars typically travelling over the track; etc. The most rigorous inspection schedule is twice weekly with at least a one calendar day interval between inspections. 49 CFR 213.233 (c). Because a number of different rail usages trigger the most rigorous inspection schedule, most of the main line railroad in the United States is required to comply with twice weekly visual inspections.
The types of anomalies to be detected by visual inspection are set forth in Part 213 of 49 CFR and generally encompass anything that affects the structure of the track or the ability of trains to operate on the track. A competent inspector will note such things as loose spikes, defective ties, weeds or other growth near the tracks, brush or other growth blocking signals, blockage in a drainage ditch, catenary wires hanging too low, or a weakness in the ballast. Track inspectors sometimes find a crack in a rail, either by seeing the crack or, if the inspector is operating a vehicle, by hearing an unusual noise indicating a problem with the rail structure. Additionally, the inspector must take measurements regarding track alignment, surface profile, surface runoff, cross-level or super elevation to ensure the track is in compliance with the federally mandated Safety Standards.
Currently, visual inspection of track is accomplished by one of two methods. In the first method, an individual inspector walks a length of track, viewing the track for anomalies. Upon detecting an anomaly, the inspector takes measurements of the anomaly; notes the type of defect, measurements taken of the defect and approximate location of the anomaly; and either takes remedial action to correct the defect or orders an appropriate remedial action. Typically, a walking inspector covers 5 miles of track each day, at a rate of approximately 1.5 miles per hour. Because the FRA requires the track to be inspected twice per week, not on consecutive days, a standard inspection schedule for a walking inspector typically involves covering a five-mile segment of track on Monday, covering a second five-mile segment of track on Tuesday, repeating the first five-mile segment on Wednesday, repeating the second five-mile segment on Thursday, with Friday scheduled as a free day, enabling the inspector to inspect track that was missed during the week, for whatever reason, or to complete whatever paperwork is required.
In the second method, a vehicle is used to travel a length of track, with one or more inspectors viewing the track through a window. The vehicle is generally a truck adapted to ride on rails, more commonly called a high rail truck. Upon detection of an anomaly, the inspector may stop the vehicle to take measurement. As in the first method, the inspector takes the measurements; notes the type, measurements, and approximate location of the anomaly; and either takes remedial action or recommends an appropriate remedial action. Inspection by vehicle typically follows an inspection schedule similar to that of a walking inspector, covering one segment of track on Monday, a second segment on Tuesday, repeating the two segments on Wednesday and Thursday, respectively, with Friday as a scheduled free day.
Many visual inspections are performed using a high rail truck. However, in areas where there is a high traffic incidence, it is not feasible to tie up the track with a high rail truck during the day, and nighttime testing with the vehicle is difficult due to lighting constraints. Hence, walking inspection is required in such areas.
In all of these inspections, the inspectors must carry or use heavy, cumbersome tools to determine such things as track alignment, surface profiles, surface runoff, cross-level, super elevation, etc. The use of these cumbersome, multiple tools causes inspector inefficiencies. The weight of the tools makes it physically difficult for the inspector to carry the tools for long distances, particularly in harsh environments and over difficult terrain. In addition, due to the weight and size of these tools, three or more inspectors are required to properly manipulate the tools in order to perform the inspections.
Accordingly, it would be beneficial to provide portable, lightweight tools which could be easily manipulated by a single inspector. This would allow one inspector to inspect more track in a day than is currently inspected by multiple inspectors, thereby increasing the efficiency and decreasing the costs of such required inspections.